There's been some posts recently related to the heads and cams that'll allow a carby 2V 750 to breathe and gain a few meaningful HP with proper setup. Brad Black's bikeboy.org website is a tremendous resource about this modification (thank you, Brad, for sharing some of your wealth of experience with the Ducati world!!).
One problem is finding the correct pieces given that heads and cams may have long been separated from their original bike. Discounting unscrupulous sellers, more often than not the problem is that sellers simply don't know what they really have and there's weird combinations of heads and cams out there, maybe due to parts-shuffles by PO's of the pieces.
So the questions, as if I might want to try to assemble this fantasy top-end setup ….
++ Is there any specific marking that clearly identifies the desirable early 900cc head with 43/38mm valves? Where are the oft-mentioned “W†and “V†marks found on the head and can anyone post pics of those?
++ Is there any specific marking that clearly identifies the cams that should be matched with these heads? Brad's site has the specs in a great table about Ducati cams, but sparse info about markings those cams may carry. Again, anyone happen to have pics of the location of those markings?
++ Or, is finding absolute telltale markings just too much to expect because Ducati was fast-and-loose about markings matching unique parts specs?
Finally, just to be sure …. There seems to have been a period of question about stud spacing and whether the early 900 carby big-valve heads can bolt-up to the 750 cylinders. Is it correct that these heads do align and bolt-up to the 750 carby cylinders (given that squish, cam timing, tuning, etc, etc all have to be properly setup in the process)?
Thanks!
[popcorn]
all great questions, I'd love to know all this myself
Belt-drive 750 heads will NOT swap onto a 900 & visa-versa.
The W and V are clearly marked and (there was no fast-&-loose markings), all V's are V heads and W's are W heads.
620 heads will pep-up a 750 a good bit, but to really kick it in the ass...
Locate some 695 heads and drop in some 11:1 Ferracci pistons. [evil]
Quote from: Duck-Stew on September 11, 2012, 12:17:59 PM
Belt-drive 750 heads will NOT swap onto a 900 & visa-versa.
The W and V are clearly marked and (there was no fast-&-loose markings), all V's are V heads and W's are W heads.
620 heads will pep-up a 750 a good bit, but to really kick it in the ass...
Locate some 695 heads and drop in some 11:1 Ferracci pistons. [evil]
did anyone ever find out if the 696 heads fit?
Quote from: Duck-Stew on September 11, 2012, 12:17:59 PM
Belt-drive 750 heads will NOT swap onto a 900 & visa-versa.
OK, so this is the stud spacing difference between "small block" 2V and "big block" 2V to use Brad's terms. On a more careful umpteeth re-read of his "Minnie" build-up report I finally comprehend that he was always working with 750 heads on the 750 block, fitting 42.5/37 (cut-down 38mm exhaust valves) and installing a 900 cam in the 750 heads.
Thank you for the needed kick in the head (so to speak [roll] ).
Quote from: Duck-Stew on September 11, 2012, 12:17:59 PM
The W and V are clearly marked and (there was no fast-&-loose markings), all V's are V heads and W's are W heads.
Largely moot given the above, but I'm still curious about where the markings are found on both heads and cams. Looking at my heads mounted on the bike (so I'm not able to see the bottom of the casting) the only marks I see are “80†stamped into the side of the vertical cylinder 'cambox' and “1P†stamped into the same location on the horizontal cylinder. Looking at various forum and eBay posts of heads for sale, many with close-ups of casting markings, I've yet to see a “V†or “Wâ€.
Are the cams stamped on the end of the shaft behind the pulley or on the 'bare' end (as in "VHT" / "OHT" for early 900ss cams)?
My “fast-&-loose markings†question was prompted by a post by Ducatiz in the Cam Identification thread (http://www.ducatimonsterforum.org/index.php?topic=56844.0) â€" I guess that had to do with the combination of head and cam between certain bikes, not the markings on each component.
Quote from: Duck-Stew on September 11, 2012, 12:17:59 PM
620 heads will pep-up a 750 a good bit, but to really kick it in the ass... Locate some 695 heads and drop in some 11:1 Ferracci pistons.
Well that sounds interesting, can you steer me to any build / dyno results threads about those evil approaches.
Thanks for the clarifications and teasers!
696 is 88 bore. 44mm intake. 38.5 exhaust
what's the bor on the 750
The W and V designation only appear on the 900 motors.
Yeah, the engine stud spacing between the 750 and 900 heads is a mile out.
The newer small case heads are a possibility. I think there was a thread where someone found the late small block heads fit, but there was a question about deck height, piston clearance, rod length, etc. Cant remember who found out what.
The V or W marks are on the front left hand side of each head, between the valve inspection cover and cam end cap.
Doug Lofgren has also done a hot 750. See his old MPS site.
Quote from: Raux on September 11, 2012, 12:55:36 PM
did anyone ever find out if the 696 heads fit?
696 heads won't bolt up to the 750 barrels, as they use head gaskets.
And the exhaust port is a different configuration, so that very likely won't work either.
Stew and I built that 750 in late '07.
695 heads with a little port match/cleanup, Ferracci 11:1 pistons.
IIRC, it already had a carb kit in it, and it did have a light flywheel in it too.
That was a snarly little 750, for sure.
No dyno info.
695 heads have the same size valves as the 900, cams are shorter duration and less lift, not necessarily worse though.
So the options for a more straight forward fit are 900V cams and valves or 695 heads. What do the 695 heads go for up there? Down here I think it would be cheaper to get 900 cams and valves.
With hi comp and good cams and valves, a 750 could embarass a stock or stockish 900, I reckon. I like how they don't choke at the top end, and many say they are a sweeter engine.
What do you say Speeddog, good project for your bike?
Sounds like even though the 750 is an 88mm bore same as the 695, full size 900 big valves may not fit in that head (Minnie had a cut-down ex valve) maybe due to angle&/or head shape. Obviously it can be done and gain was on the order of 10% in Minnie's case.
The 695 swap as described above might be a bit more straightforward, assuming that combustion chamber is designed to take advantage of the larger valves. What manifolds/runners were used 'tween heads and carbs on that project?
Quote from: carbmon on September 11, 2012, 06:12:06 PM
~~~SNIP~~~
What manifolds/runners were used 'tween heads and carbs on that project?
Standard 750 carby runners, manifolds, carbs, etc.
Quote from: koko64 on September 11, 2012, 04:25:38 PM
~~~SNIP~~~
What do you say Speeddog, good project for your bike?
I've been tempted, as I've got all the bits to do it, save for the hi-comp pistons.
But that's where it goes sideways.
I'd have to pull the heads off of my 695 engine that's complete other than a clutch.
And then buy the hi-comps.
And pretty much re-create Brad's 750, IMO.
I've got the bits to try it with 900ie cams, and ST2 cams.
Which would be interesting.
But I've got nobody that will pay for the experiment, so it's tough to justify.
For a little bit more money and effort, I'd buy 800 hi-comps, tear the 695 down, and install the 800 crank that I've got.
Or even a DS1k crank I've got.
Ending up with an 803 or 870 small-case 6-speed.
Quote from: Speeddog on September 11, 2012, 08:27:24 PM
I've been tempted, as I've got all the bits to do it, save for the hi-comp pistons.
But that's where it goes sideways.
I'd have to pull the heads off of my 695 engine that's complete other than a clutch.
And then buy the hi-comps.
And pretty much re-create Brad's 750, IMO.
I've got the bits to try it with 900ie cams, and ST2 cams.
Which would be interesting.
But I've got nobody that will pay for the experiment, so it's tough to justify.
For a little bit more money and effort, I'd buy 800 hi-comps, tear the 695 down, and install the 800 crank that I've got.
Or even a DS1k crank I've got.
Ending up with an 803 or 870 small-case 6-speed.
Fair enough.
The newer motor will be better I guess.
I need a wealthy sponsor too. ;D
SPEEDDOG > would hi comp pistons and big cams work with my F.I. M750 ?
Well this has been a hugely informative thread for me, thanks to the 'experts' for sharing their experience.
The 695 head swap sure looks tempting for the next phase of fun with my carby M750 toy.
For now I think I'll leave the engine alone and finish the frame cleanup, re-wire and repaint project I have in progress, watching forums and eBay for the necessary pieces in the mean time.
One Two Three last (yeah, sure) questions for now .... does the 695 as stock have adjustable cam pulleys and Speeddog, on your prior 695 head swap, do you recall where you ended up setting the cam timing on that project (going for the gold in trying to tap your experience here ;) )? Any idea what the valve/piston clearance was with that setup?
So one version of the fantasy carby 750 top-end might be:
+ 695 heads & cams
+ 11:1 pistons
+ OEM long intake runners with my current 39 FCRs
+ adjustable cam pulleys to be able to dial-in cam timing
+ Ignitech unit to be able to dial-in ignition timing
+ Dyno time for stock baseline and to get the 695 setup tuned and see what the real gains are
Quote from: koko64 on September 11, 2012, 04:25:38 PM
So the options for a more straight forward fit are 900V cams and valves or 695 heads. What do the 695 heads go for up there? Down here I think it would be cheaper to get 900 cams and valves.
~~~SNIP~~~
The heads we used were nearly brand new, and IIRC were ~$500.
But we bought them from a bandit....
Should be able to find a set for about those $ now.
Quote from: H-2 CHARLIE on September 12, 2012, 12:28:03 AM
SPEEDDOG > would hi comp pistons and big cams work with my F.I. M750 ?
Brad Black did a 750SSie with big cams:
http://www.bikeboy.org/750ss_900carb_cams.html (http://www.bikeboy.org/750ss_900carb_cams.html)
Likely would work well.
But, he did a lot of fueling work, so you've got to consider that in the budget as well.
Quote from: carbmon on September 12, 2012, 06:29:26 AM
~~~SNIP~~~
One Two Three last (yeah, sure) questions for now .... does the 695 as stock have adjustable cam pulleys and Speeddog, on your prior 695 head swap, do you recall where you ended up setting the cam timing on that project (going for the gold in trying to tap your experience here ;) )? Any idea what the valve/piston clearance was with that setup?
~~~SNIP~~~
Yes, 695 has the adjustable pulleys.
We left 'em in the stock position.
I've got no info on what the valve/piston clearance was, I suspect we just got lucky. :P
I wouldn't build it again without setting cam timing and checking clearance.
Quote from: Speeddog on September 12, 2012, 09:44:58 AM
.....
Yes, 695 has the adjustable pulleys.
We left 'em in the stock position.
I've got no info on what the valve/piston clearance was, I suspect we just got lucky. :P
I wouldn't build it again without setting cam timing and checking clearance.
Thanks again for all the info. Sounds like everything would fit-up pretty straightforward, it might be interesting to see what that cam profile would do to the TQ/HP curves on the longer-stroke 750. It seems that the same profile is used in the longer stroke 800, too, so that really suggests to me it is worth a shot on the 750. Couldn't be any worse that the stock small valve heads/cams fer sure.
Keep me in mind if you run across any of the needed bits [thumbsup]
the 696 cylinder and head swap sounds interesting. might have to order a base gasket to see if they're the same.
Quote from: brad black on September 14, 2012, 02:32:45 AM
the 696 cylinder and head swap sounds interesting. might have to order a base gasket to see if they're the same.
OK, I'll bite ... what about the 696 approach strikes you as more intriguing than the 695 heads?
+1/+.5 valve size?
+4deg overlap cam?
With the 696 having 4.3mm shorter stroke than the 750, would you anticipate any clearance problems (is the deck height of the 696 jug likely to work OK with the 750's longer-stroke crank)?
Just trying to tap a little deeper into that experience base you bring to the table ;)
I've been spending more keyboard time 'running traps' on the 695 head swap idea. Obviously since Speeddog has done 695 heads on the 750 carby, I don't have to worry about basic fitment for that specific swap and I'm using that as a 'baseline known-to-fit' for my research.
This approach is attractive to me because the head is a more modern design than the 750 carby and to fit larger valves into the 750 head requires a lot of machine work I'd have to outsource at great expense. I can manage bolt-up swapping and tuning time, and even a bit of port-matching, but extensive machining is out of my league. Bummer, though, that there's only one cam profile that will direct-fit in the 695 head due to the camshaft bearing arrangement apparently only shared with the 800 that uses the same cam.
I've been mainly looking to see if the 800 head with the same bore, cam and valve diameter is a candidate in addition to the 695 head, hoping that would expand the pool of source heads. With Brad's post I've expanded to look at a few of the 696 parts fiche pages to see what I could tell about what that approach might entail.
Interesting to find that the 695 vs 800 'complete heads' are different part numbers. Note that 'complete heads' include the guides and seats, there's no part number available for only the head casting. The part numbers of the head pieces (valves, seats, guides, seals, rockers, cam, etc) are the same between the 695 and 800 EXCEPT the valve guides and valves (but the valve seals and seats are the same) ?!? Wondering what the deal is there.
The throttle bodies are the same diameter though inlet runners are different part numbers. I haven't found info on the exhaust port diameter. All this makes me wonder if the 800 head is different from the 695 in some way other than maybe the material of the valves and guides (stem diameter must be the same if the valve seal part number is the same, right?)
No reason to expect the 696 heads to have much part commonality with those since about all that's shared in the head/cam design with the 695/800 in the bore. So not really possible to check fitment compatibility by running part number checks against the 'proven' 695 heads.
I get comfort finding that the timing belts are the same for 750/695/800 (noting that it is different for the 696 â€" is that likely just a length issue or did they change the belt width/cog profile/cog spacing or pulley diameters on either end?) Part of the reason I wonder about the belt is that the 696 drive roller on the layshaft end is different from the 695/800 part number. Maybe this is a silly tangent but it seems important to me that I'm able to get belts of the correct fit for any swap and there's lots of potential dimensional variables between the layshaft and the camshaft that could affect that it seems (layshaft-to-base, base-to-deck, deck-to-camshaft, pulley diameter, etc).
It'd be nice to be in a shop with a steady stream of different bikes to explore for potential swap projects, but lacking that I'm stuck with surfing parts fiche, resources like Brad's tables and reports (sure would be neat if the “Comparison of 2V Models" were expanded to include the 695 and 696 ;)), and forums like this one with folks that have tried different things.
All good fun without a doubt. ;D
I have an extra 696 head that can be used for testing
i trashed the exhaust port practicing port/polish
Gee, I wish I were closer to Kaiserslautern so it'd be practical for me to take you up on that offer !
Shipping to Texas would be a bear I imagine :'(
Though the valves are a bit bigger than the 695/800 head, pending Brad offering why he's interested in that approach, the only thing that would make that experiment attractive to me is the option of a few more cam profiles than the 695/800 (1000DS and maybe 796 according to his report info). Could be that he says the overlap difference is a potential big bonus, and it'd have to be for me to venture into that 'unproven' swap with all the potential fitment challenges.
The 'proven' 695 swap is still really attractive, Speeddog's comment that the result was "snarly" is enough of a teaser though before and after dyno data would be nice of course. Again, given the starting point of the 750 head/cams, it's hard to imagine the 695 swap could be anything other than better.
Kinda pressed for time right now, but I''ll be back with more thoughts on the 696 vs. 695.
the 2006 s2r800 has 8mm valve stems, the 2007 has 7mm stems. 2007 695 and 800 share the same heads.
will ramble more later.
Quote from: brad black on September 14, 2012, 09:23:45 PM
the 2006 s2r800 has 8mm valve stems, the 2007 has 7mm stems. 2007 695 and 800 share the same heads.
will ramble more later.
Man, your shared knowldege base is great.
I was comparing parts fiche between 2007 M695 and 2004 M800 and missed until I just re-checked that the valve guides are also different part numbers.
I now see that the '07 S2R and '07 M695 have the exact same 'complete head' part numbers so that opens the pool of parts for the 695 swap as done by Speeddog to '07-'08 695 and '07 S2R 800. Are the earlier '04-'07 800 heads the same except for the valve stems? Could the earlier 'large-stem' heads be 'upgraded' to the later 7mm guides/valves/valve seals (is the nominal guide OD the same for both versions)?
Quote from: Speeddog on September 14, 2012, 07:15:16 PM
Kinda pressed for time right now, but I''ll be back with more thoughts on the 696 vs. 695.
I certainly look forward to hearing your thoughts on this, Speeddog - thanks for sharing your knowledge base, too [thumbsup]
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Quote from: Raux on September 15, 2012, 01:34:42 AM
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Nice parts, for sure, but the price is breathtaking.
Re: 696 vs 695
696 head is ~ model year 2008, vs. 2005 for the 800/695 head.
Most recent technology....
Additionally, it's the updated design like what first came out on the 1000DS, with the short exhaust port.
It's got to be ~1" shorter, and that really helps to keep heat out of the head.
And the DS ports are better than the 900 ports.
I'm not particularly sold on the 7mm valves for a 2-valver.
I've seen quite a few broken half rings on DS1000's.
Quote from: Speeddog on September 15, 2012, 11:18:52 AM
Re: 696 vs 695
696 head is ~ model year 2008, vs. 2005 for the 800/695 head.
Most recent technology....
Additionally, it's the updated design like what first came out on the 1000DS, with the short exhaust port.
It's got to be ~1" shorter, and that really helps to keep heat out of the head.
And the DS ports are better than the 900 ports.
I'm not particularly sold on the 7mm valves for a 2-valver.
I've seen quite a few broken half rings on DS1000's.
What about basic fitment issues … again just looking at fiche … Looks like the locating dowels are different on the 696 head compared to the 750/695/800? The 696 head is designed for a gasket while the 695/750/800 is not? Also looks like the ports/spigots are maybe different enough to cause some real fun with fitting the 750 intakes and exhaust?
Maybe the 696 is the ultimate fantasy head from among currently available parts (well, I did invite that in the thread title) but my initial reaction is that'd be a lot bigger project than the '07-'08 695/800 approach (inviting further comment).
Re: 7 vs 8mm valve stems …
For this 750 carby swap is that concern big enough that you would look to pre '07 800 heads to get the 8mm stems? When I started looking at prices for new valves, that alone blows the economics for a change even if it could be done. To make this work I'll have to patiently shop for a set of complete heads and hope the valves are good enough to keep, anticipating new guides, seals & relap at the most.
If the answer is yes, do you know which pre '07 heads are a 'match'? All the way back to the '03 Monster 800? What about ss800's back to '03?
all the 800 heads would be the same. apart from the guides. i'd say the 7mm stems just lead to faster guide wear, but i'd not be overly concerned about either. they can all break collets, possibly a combination of rpm and valve weight. altho i have seen a 600 do it too.
you'll need some high comp pistons as the 800 chamber will be quite a bit bigger, it's basically the old 900 chamber.
but otherwise it'll be a good swap i'd say. easier than getting them big valved and finding 900 cams.
probably just as easy to get an 800 motor and fit it tho. you get a 6 speed that way.
to fit the 696 heads you'd need to fit the cylinders as well. given the 696 is a shorter stroke, the rods appear to be the same (xx1A vs xx2A #) and the inlet ports appear to be in the same place the piston should be 2mm or so longer. so you'd machine 2mm or so from the top of the 696 pistons as required to fit the chamber profile and increase your comp as well. you'd need to get the valve reliefs deepened too i assume. the manifolds should fit straight up. you'd have to fabricate exhaust as required.
but there's a lot of assumptions there.
Quote from: brad black on September 15, 2012, 04:50:07 PM
all the 800 heads would be the same. apart from the guides. i'd say the 7mm stems just lead to faster guide wear, but i'd not be overly concerned about either. they can all break collets, possibly a combination of rpm and valve weight. altho i have seen a 600 do it too.
Cool, that opens the pool of parts a bit.
Quote from: brad black on September 15, 2012, 04:50:07 PM
you'll need some high comp pistons as the 800 chamber will be quite a bit bigger, it's basically the old 900 chamber.
Higher compression pistons are a given for the project.
Would you suggest the “11:1†designed for the 750 or go up to the “12:1â€, expecting the as-installed ratio to end up a lot lower than the 'as-stated' ratio with the bigger heads?Quote from: brad black on September 15, 2012, 04:50:07 PM
but otherwise it'll be a good swap i'd say. easier than getting them big valved and finding 900 cams.
probably just as easy to get an 800 motor and fit it tho. you get a 6 speed that way.
Understood. Maybe very close to a cost-wash, too, considering that the high-comp pistons required for the head swap seem to be pretty rare on the used market.
BTW, I assume that the sensor assy on the 695/800 H head can just be pulled and blocked for a carby installation?Quote from: brad black on September 15, 2012, 04:58:22 PM
to fit the 696 heads you'd need to fit the cylinders as well. given the 696 is a shorter stroke, the rods appear to be the same (xx1A vs xx2A #) and the inlet ports appear to be in the same place the piston should be 2mm or so longer. so you'd machine 2mm or so from the top of the 696 pistons as required to fit the chamber profile and increase your comp as well. you'd need to get the valve reliefs deepened too i assume. the manifolds should fit straight up. you'd have to fabricate exhaust as required.
but there's a lot of assumptions there.
Yeah, the fair amount of machine work + lots of assumptions still to be proven make the 696 route a bit more of a challenge (and expense) than I'd personally want to undertake.
FYI, 696 heads have 20 tooth pulleys, where the 750's have 18 tooth.
So you would have to swap one way or the other....
Quote from: Speeddog on September 26, 2012, 05:28:22 PM
FYI, 696 heads have 20 tooth pulleys, where the 750's have 18 tooth.
So you would have to swap one way or the other....
So what's the tooth count on the bottom for each (sittin' here bored, drawing a sketch and thinking about cam timing)? Just a mental diversion, definitely not a project I'd undertake.
Noticing the availability of complete engines compared to just heads on eBay ... I'm back with Brad's 'just swap-in an entire 800' comment, trying to think through the steps of the carb/timing tuning process with that engine wrapped in 39 FCR's and an Ignitch unit instead of the FI system.
You know, simple questions like "given 39 FCR's setup for the stock 750, and a 'dumb' new Ignitech box" .... how do you set 'em up to just start the thing and get it to run good (and safe) enough for a start at tuning?
Yeah, if not already obvious, this is the clue that I'd be in way over my head on any of these projects (pardon the pun).
The 696 has 20 on the drive pulley, 750 has 18.
All are 1:1 from the drive to the head.
Seeing as an 800 will pull nearly the same HP as a 900, I'd go with 41's.
800 motor swap tips:
Intake & exhaust manifold placement is the same so just swap the 750 parts on & go.
2005-6 800 motors have the wet-slipper clutch, 6-speed trans & 8mm valve stems (8mm have the good valve guides which hardly ever go soft)
You'll still have to deal w/the 10mm to 12mm engine mounting bolts, but that's minor.
You'll have to get the single timing pick-up to fire both ignition coils (Ignitech)
Quote from: Speeddog on September 27, 2012, 10:17:58 PM
All are 1:1 from the drive to the head.
Cool, much simpler that way.
Quote from: Speeddog on September 27, 2012, 10:17:58 PM
Seeing as an 800 will pull nearly the same HP as a 900, I'd go with 41's.
Aha, clarity … I'd not thought of it that way. I've got the 39's and I recall seeing something (I think on Brad's site) about him playing with 39's on a client's 900.
So, if one started by setting up the carbs as they would be for a similar HP motor, that might be a good ballpark to get things going?
Quote from: Duck-Stew on September 28, 2012, 07:09:34 AM
800 motor swap tips:
Intake & exhaust manifold placement is the same so just swap the 750 parts on & go.
2005-6 800 motors have the wet-slipper clutch, 6-speed trans & 8mm valve stems (8mm have the good valve guides which hardly ever go soft)
You'll still have to deal w/the 10mm to 12mm engine mounting bolts, but that's minor.
You'll have to get the single timing pick-up to fire both ignition coils (Ignitech)
Thanks! I knew about the 6-speed and someone here already clued me about the 8mm vs 7mm stem/guide issue but I wasn't aware of the slipper. So just for clarification … are other/later years (800) with the wet clutch non-slipper?
Yeah, the bolt thing is a non-issue it seems, easy fix with careful overbore of the frame.
The Ignitech has provisions for the single pickup programming, so that shouldn't be a problem.
I still wonder about how to find a good initial timing curve for the Ignitech on the 800. I wondered if the OEM 800 timing map is known/published and if replicating that as close as possible in the Ignitech would be a good starting point for a carby version (taking care to match the base advance)? I understand that without a TPS/MAP (not going there!) the number of points available on the Ignitech map is somewhat limited so the timing 'curve' might not be as smooth as the OEM FI timing curve, but so it goes.
Just concerned about a starting point for all the stuff fuel delivery/ignition related from the standpoint of not wanting to melt/burn anything (other than fuel!) in the combustion chamber right out of the box. “Optimizing†( I know Brad doesn't like that term) could then follow.
I should ask directly … has anyone here done an 800FI to carby conversion?
2003-4 800's are wet-clutch 5 speeds.
2007-8 800's are 6-speed, wet slipper clutch but have the 7mm valve stems.
Because of the similarities of the 900 and 800 combustion chamber, I'd start w/the 900 ignition map and go from there. It'll likely be close (my guess).
You will likely need to adjust, but the 900 carb tuning would be a good start (since they're making roughly the same power).
DS
What's the stock compression ratio of the 800?
Quote from: koko64 on September 28, 2012, 12:11:29 PM
DS
What's the stock compression ratio of the 800?
IIRC: 10.8:1 (Could be 10.6:1...)
10.4, +/- 0.5.
i can't believe how many engines there are on usa ebay. heaps of 620, but quite a few 800 and 900, etc. and so many 1098. see if you can jam one of them in.
if you're going to fit an 800 i'd just get a 900. it's a stronger motor.
1198 motor in a Monster 1100 [evil]
Quote from: brad black on September 29, 2012, 12:34:22 AM
.....i can't believe how many engines there are on usa ebay. heaps of 620, but quite a few 800 and 900, etc. and so many 1098. see if you can jam one of them in.
if you're going to fit an 800 i'd just get a 900. it's a stronger motor.
LOL
750 head mods>800>900>1098+ in my former business we called that "project creep" [laugh]
I understand what you're saying about the 900, a well-proven easy swap, too.
Shoot me for sacrilege but I like the quiet of the wet clutch and the look of the engines without the external oil lines for my project's styling goals.
Always a matter of personal preference at the bottom line, ya know [thumbsup]
wet clutch i can understand. you can always seal the cover on the dry clutch and run oil in it. works well.
external oil lines are pre 98 only. the air cooled only cylinders are 98 and 99 i think, i've had 2000 models apart that are oil cooled without external lines.
the fact you can run with much lighter clutch springs to reduce lever effort and you effectively have another gear plus it's all stronger is what makes the 900 motor attractive to me. now that i've hotted up a 750 i'd not do it again, i don't see the point when the alternative is easy. i only did mine because no one had ever asked me to do one. for what it is it's a good result, nearly as powerful as an 800 with the basic inlet and exhaust mods. which, when you say it like that, makes it sound like a waste of effort.
i've owned 4 (i think) 6 speed ducatis and the 5 speed is like the 6 speed without 6th. the extra gear makes the engine so much more usable as an all rounder.
the small motor 6 speed has a narrower spread than the 900 box, but it's still better.
^^^ The continuing education here is great. ^^^
Thanks Brad!
I've been searching for a 6th gear for a while now on the 750 :-\ tempting to change the sprocket sizes a bit to see if it helps but I don't think it will much...